Giuliani appeared at the fourth annual benefit dinner of the Insurance Industry Charitable Foundation honoring Greenberg, who is the current chairman and CEO of C.V. Starr & Co. He called Greenberg “a remarkable American” and a “patriot.”

Mr. Giuliani added: I think what was done to him was one of the great outrages in American legal history,” referring to Mr. Greenberg’s forced retirement from AIG in 2005 during an accounting scandal that subsequently saw an AIG executive and four executives from General Reinsurance convicted of manipulating AIG’s financial statement.

Clearly referring to Mr. Spitzer, but not referring to him by name, Mr. Giuliani said: “And the person who was doing it is terrible on television,” adding,: “What a nit-wit.”

Mr. Spitzer, who was elected governor of New York in 2006 and resigned in disgrace after a liaison with prostitutes was uncovered in 2008, is now host of an evening talk show on CNN.